I used the Virtuoso card and I'm not going to use it again. I'm a big believer that you should either save up for what you want or attempt to pay in full.
The problem with anything like the Virtuoso is that you only get the interest free for a period of time and then it reverts to a 29.9% loan (APR may have changed) if you don't manage to pay it off on time or simply forget. It works as follows: you pay off a small amount per month, during the interest free period and then are liable for the 'lump sum' at the end of this period. If you're struggling financially at the time or forget to pay this lump sum, you end up with a 29.9% loan for the remaining amount of money owed.
This happened to me. I was working abroad at the time, was paying it off as planned, but completely forgot that the period of interest free was coming to an end. Missed paying of the 'final lump sum' and ended up on the 29.9% interest rate. However, I quickly paid that off, when I returned to the UK.